KR101345646B1 - Method for preparing of polyamide copolymer - Google Patents

Abstract

The present invention relates to a method for producing a polyamide copolymer using ω-aminoalkanoic acid, the polyamide copolymer thus prepared is highly hygroscopic, improves the spin processability and heat resistance, and is highly useful and economical.

Description

Method for preparing polyamide copolymer {Method for preparing of polyamide copolymer}

The present invention relates to a novel method for producing a polyamide copolymer, and more particularly, to a method for producing a polyamide copolymer having high hygroscopicity and radiation resistance.

Many studies have been made on new synthetic fibers that can simultaneously utilize the advantages of cotton such as high hygroscopicity and excellent fit while maintaining the advantages of conventional synthetic fibers.

Hygroscopicity of crystalline polymers is usually dependent on several factors such as hydrophilic functional group, crystal structure, crystallinity, etc. In the case of nylon, one of the crystalline polymers, when the number of lipophilic carbon is reduced compared to the hydrophilic amide group, In view of the increase in hydrophilicity and the increase in hygroscopicity, research on nylon 3 or nylon 4 having fewer carbons than nylon 6 has been in depth.

In 1953, Ney et al. Dehydrated by heating at 90 to 120 ° C. using potassium hydroxide to dehydrate and heated to 160 ° C. under nitrogen stream to ring-open polymerize 2-pyrrolidone for the first time to synthesize nylon 4. Based on this method, technologies such as new catalyst systems and polymerization methods have been developed for the purpose of high molecular weight, polydispersity control, and simplification of the manufacturing process from the 1950s to the 1990s.

Polymerization of nylon 4 resin and fabrication of fibers using the same was actively carried out by Chevron Research from the 1970s to 1980s, mainly on the pilot scale, catalytic studies, polymerization process studies, thermal stabilization studies, But it did not succeed in commercialization.

In addition, nylon 4 (Poly (2-pyrrolidone)) resin synthesized in 1953 has a low lipophilic carbon per repeat unit in structure, so it has excellent hygroscopicity and excellent rigidity. Although it appeared in history as a synthetic fiber, its melting point is 265 ℃ but its pyrolysis temperature is 260 ℃ .There is a technical problem with extremely poor heat processing heat resistance.At this time, high price and supply instability of monomer 2-pyrrolidone For this reason, it has not been commercially successful for over thirty years and has been immersed in history.

On the other hand, in relation to polyamide copolymers, Korean Patent Registration Nos. 10-580869 and 10-0417927 disclose inventions on polyamide copolymers or polyamide fibers, but improve spinning processing heat resistance while maintaining the advantages of nylon 4. Polyamide copolymers have not been reported yet, and there has been a need for development thereof.

The problem to be solved by the present invention is to provide a method for producing a polyamide copolymer having a high hygroscopicity and improved spinning processability and heat resistance through a simple reaction.

In order to solve the above technical problem, the present invention provides a method for producing a polyamide copolymer by a) polymerizing a) 2-pyrrolidone or γ-aminobutyric acid and b) ω-aminoalkanoic acid having 5 to 36 carbon atoms. to provide.

According to one embodiment of the present invention, the reaction molar ratio of a) and b) may be 1:99 to 99: 1, and 30:70 to 99: 1 is preferable.

Examples of ω-aminoalkanoic acid usable in the present invention include 12-aminododecanoic acid, 6-aminocaproic acid or caprolactam and the like.

In addition, according to another embodiment of the present invention, the polymerization reaction is preferably carried out by increasing the temperature step by step from 150 ℃ to 280 ℃, it can be carried out for 7 hours to 23 hours.

According to the present invention, it is possible to provide a polyamide copolymer having improved spinning processability and heat resistance by inducing a decrease in melting point and an increase in pyrolysis temperature while maintaining high hygroscopicity, and it is possible to use a production facility such as nylon 6 fiber which is already commercialized. It is highly applicable and economical to the actual process.

1 is a graph showing NMR data of the polyamide copolymer prepared in Example 1-1 of the present invention.
2 is a graph showing the results of thermal analysis (DSC) of the polyamide copolymer prepared in Examples 1-1 to 1-5 of the present invention.
3 is a graph showing the results of thermal analysis (DSC) of the polyamide copolymer prepared in Examples 2-1 to 2-3 of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Nylon 4 has a melting point of 265 ℃ and higher than nylon 6, but pyrolysis temperature of 260 ℃ due to the nature of the spinning should be melt spinning at a temperature above the melting point, there is a problem that the nylon 4 polymer is pyrolyzed and continuous spinning is impossible. .

In general, pyrolysis of a polymer can be classified into chain depolymerization and random pyrolysis. The former is a mechanism in which chains are lost in monomer units at chain ends or weak bonds. It refers to the mechanism by which random cleavage occurs at any location. Generally, condensation polymers such as nylon are dominant in random pyrolysis, but two mechanisms are combined. Further, when water is present at a high temperature, pyrolysis can be accelerated due to hydrolysis of the amide bond.

In general, when pyrolysis of nylon at high temperature, the production of CO ₂ , H ₂ O or NH ₃ is mainly increased by decarboxylation and deamine reaction. In addition, water may be produced by condensation and dehydration, and polymer amines or nitriles may also be produced.

In addition, oxidative pyrolysis occurs when nylon resin is heated to high temperature in the presence of oxygen, and trace impurities such as metal ions, carbonyl compounds, and hydroperoxides in the polymer absorb energy. By generating stray free radicals to initiate a chain reaction. In the case of nylon, the reaction starts mainly on the methylene group attached to the amide nitrogen, that is, the α-carbon. Free radicals first remove hydrogen to form carbon radicals, where oxygen combines to produce peroxy radicals. This causes the chain reaction by leaving hydrogen back from the polymer chain to produce hydroperoxide and another alkyl radical. Hydroperoxides can be broken down to form alkoxy radicals and hydroxy radicals and to initiate new chain reactions.

On the other hand, pyrolysis causing yellowing of nylon resin is largely due to the production of unsaturated conjugated oligoenimine. Enimine is colored by absorbing ultraviolet and visible light. As time goes by, the conjugation proceeds more and the more conjugation becomes, the longer the wavelength is absorbed and the yellowing phenomenon is intensified. Oligoenimines are made by reaction of amine end groups with aldehydes.

For nylon 4, the problem of heat resistance is that the equilibrium between the polymer and the monomer in the molten state is towards the monomer. For these reasons, factors affecting the thermal stability of the nylon 4 polymer include end groups, impurities in the polymerization catalyst, molecular weight distribution, presence or absence of side chains, and irregularities in the structure.

The present invention utilizes the monomer 2-pyrrolidone or γ-aminobutyric acid and 5 to 36 carbon atoms in order to maximize the high hygroscopicity, which is the strength of the nylon 4 polymer, and at the same time significantly improve the heat-processing heat resistance. A polyamide copolymer obtained by polymerizing aminoalkanoic acid and a method for producing the same are provided. The polyamide copolymer obtained by polymerizing the 2-pyrrolidone or γ-aminobutyric acid and ω-aminoalkanoic acid having 5 to 36 carbon atoms has important properties such as hygroscopicity, melting point, and thermal decomposition temperature depending on the type and composition of the raw materials. Since it is different, by adjusting it appropriately, high hygroscopicity and radiation heat resistance can be ensured simultaneously.

The polyamide copolymer prepared according to the present invention is characterized by including a repeating unit represented by the following formula (1).

(1)

(One)

Where

n is an integer from 5 to 36,

x + y = 1, 0 <x <1, and 0 <y <1.

It is further more preferable that it is 0.3 <x <1, and 0 <y <0.7 here. The reason is that the content such as high hygroscopicity is fully exhibited when the content of nylon 4 is 30% or more.

The present invention provides a method for producing a polyamide copolymer comprising a repeating unit represented by the formula (1) by polymerizing 2-pyrrolidone or γ-aminobutyric acid and ω-aminoalkanoic acid having 5 to 36 carbon atoms. It is characterized by not using an initiator.

The polyamide copolymer obtained by polymerizing the 2-pyrrolidone or γ-aminobutyric acid and ω-aminoalkanoic acid having 5 to 36 carbon atoms has important properties such as hygroscopicity, melting point, and thermal decomposition temperature depending on the type and composition of the raw materials. Since it is different, it is possible to secure ultra-hygroscopicity and radiation heat resistance at the same time by appropriately adjusting this. The molar ratio of 2-pyrrolidone or γ-aminobutyric acid and the aminoalkanoic acid may be appropriately adjusted according to the properties of the polyamide copolymer to be prepared, and may be blended in a molar ratio of 1:99 to 99: 1. It is possible to do this, and it is preferable to mix | blend in molar ratio of 30: 70-99: 1.

 In addition, after mixing 2-pyrrolidone or γ-aminobutyric acid and ω-aminoalkanoic acid having 5 to 36 carbon atoms, the polymerization temperature is preferably performed by gradually raising the temperature from 150 ° C to 280 ° C. The temperature rising process may be performed, for example, for 7.5 hours to 23 hours from 150 ° C to 280 ° C.

Hereinafter, the present invention will be described in detail through examples. However, the following examples are intended to help the understanding of the present invention, and the scope of the present invention should not be construed as being limited thereto.

Example 1-1

Into the flask, 3.7 g (0.036 mol) of γ-aminobutyric acid monomer and 70 g (0.325 mol) of 12-aminododecanoic acid were mixed in a nitrogen atmosphere, followed by 2 hours at 190 ° C and 2 hours at 230 ° C. The reaction was carried out at 250 ° C. for 4 hours.

Examples 1-2

Example 1-1 was carried out in the same manner as in Example 1-1 except that 14.4 g (0.140 mole) of γ-aminobutyric acid and 70 g (0.325 mole) of 12-aminododecane acid were mixed. An amide copolymer was prepared.

Example 1-3

Example 1-1 was carried out in the same manner as in Example 1-1 except that 22.3 g of γ-aminobutyric acid (0.216 mol) and 70 g (0.325 mol) of 12-aminododecanoic acid were mixed. An amide copolymer was prepared.

Example 1-4

Polyamide was prepared in the same manner as in Example 1-1, except that 27.4 g (γ66 mol) of γ-aminobutyric acid and 70 g (0.325 mol) of 12-aminododecanoic acid were mixed in Example 1-1. Copolymers were prepared.

Examples 1-5

Polyamide was prepared in the same manner as in Example 1-1, except that 33.5 g (0.325 mol) of γ-aminobutyric acid and 70 g (0.325 mol) of 12-aminododecanoic acid were mixed in Example 1-1. Copolymers were prepared.

In addition, NMR data of the polyamide copolymer prepared in Example 1-1 was measured, and the results are shown in Figure 1 below. Referring to FIG. 1, it can be seen that the polyamide copolymer prepared in Example 1-1 is a polyamide copolymer which is a copolymer of γ-aminobutyric acid and 12-aminododecane acid.

The composition and production conditions of the polyamide copolymers prepared in Examples 1-1 to 1-5 are summarized in the following [Table 1]. In addition, the brittleness or toughness of the polyamide copolymers prepared in Examples 1-1 to 1-5 were measured, and the results are also shown in Table 1 below.

In addition, the polyamide copolymer prepared in Examples 1-1 to 1-5 was dried in a vacuum oven at 80 ℃ for 4 hours, dissolved in formic acid at 40 ℃ to measure the concentration and intrinsic viscosity The results are also shown in Table 1 below.

On the other hand it can be seen that the polyamide copolymers prepared in Examples 1-1 to 1-5 have a similar or better intrinsic viscosity than nylon 12.

Ingredients (mol) Brittleness
Evaluation results density
(g / ml) Intrinsic Viscosity (ml / g) γ-aminobutyric acid 12-aminododecanoic acid Example
1-1 10 90 toughness 0.3 1.148 Example
1-2 30 70 toughness 0.720 Example
1-3 40 60 toughness 0.772 Example
1-4 45 55 toughness 0.796 Example
1-5 50 50 toughness 0.790 Nylon 12 100 toughness 0.790

Referring to [Table 1], it can be seen that the polyamide copolymers prepared in Examples 1-1 to 1-5 have excellent toughness and improved spinning processability and heat resistance while maintaining high hygroscopicity.

Ingredients (mol) T _m (℃) △ H _m (J / g) γ-aminobutyric acid 12-aminododecanoic acid Example
1-1 10 90 178 36.9 Example
1-2 30 70 172 37.6 Example
1-3 40 60 165 38.5 Example
1-4 45 55 164 37.0 Example
1-5 50 50 160 35.7 Nylon 12 100 178 39.7

Referring to [Table 2] and [FIG. 2], it can be seen that the melting temperature (T _m ) is lowered as the content of γ-aminobutyric acid in the polyamide copolymer increases. Accordingly, it can be seen that a polyamide copolymer having improved spinning processability and heat resistance can be obtained by inducing a decrease in melting point and an increase in pyrolysis temperature while maintaining high hygroscopicity.

Example 2-1

15 g (0.176 mol) of monomer 2-pyrrolidone and 88.6 g (0.411 mol) of 12-aminododecanoic acid were mixed in a flask under nitrogen atmosphere, and 3 hours at 190 ° C, 2 hours at 230 ° C, and 6 at 250 ° C. It was prepared by reacting for a time.

Example 2-2

A polyamide was prepared in the same manner as in Example 2-1, except that 20 g (0.235 mol) of 2-pyrrolidone and 75.9 g (0.352 mol) of 12-aminododecanoic acid were mixed in Example 2-1. Copolymers were prepared.

Example 2-3

A polyamide was prepared in the same manner as in Example 2-1, except that 25 g (0.294 mol) of 2-pyrrolidone and 63.3 g (0.294 mol) of 12-aminododecanoic acid were mixed in Example 2-1. Copolymers were prepared.

The composition and production conditions of the polyamide copolymer prepared in Examples 2-1 to 2-3 are summarized in the following [Table 3]. In addition, the brittleness or toughness of the polyamide copolymers prepared in Examples 2-1 to 2-3 were measured, and the results are also shown in Table 3 below.

In addition, the polyamide copolymer prepared in Examples 2-1 to 2-3 was dried in a vacuum oven at 80 ℃ for 4 hours, and then dissolved in formic acid at 40 ℃ to measure the concentration and intrinsic viscosity The results are also shown in Table 3 below.

Ingredients (mol) Brittleness
Evaluation results density
(g / ml) Intrinsic viscosity
(ml / g) 2-pyrrolidone 12-aminododecanoic acid Example
2-1 30 70 toughness 0.3 1.0881 Example
2-2 40 60 toughness 0.9038 Example
2-3 50 50 toughness 0.8020 Nylon 12 100 toughness 0.790

Referring to [Table 3], it can be seen that the polyamide copolymers prepared in Examples 2-1 to 2-3 have excellent toughness and improved spinning processability and heat resistance while maintaining high hygroscopicity.

On the other hand, it can be seen that the polyamide copolymers prepared in Examples 2-1 to 2-3 have an intrinsic viscosity better than that of nylon 12.

Meanwhile, the polyamide copolymers prepared in Examples 2-1 to 2-3 were thermally analyzed (DSC), and the results are shown in Table 4 and FIG. 3.

Ingredients (mol) T _m (℃) △ H _m (J / g) 2-pyrrolidone 12-aminododecane acid Example
2-1 30 70 194 48.7 Example
2-2 40 60 168 40.5 Example
2-3 50 50 158 41.0 Nylon 12 100 178 39.7

Referring to [Table 4] and [FIG. 3], it can be seen that the melting temperature (T _m ) is lowered as the content of 2-pyrrolidone is increased in the polyamide copolymer. Accordingly, it can be seen that a polyamide copolymer having improved spinning processability and heat resistance can be obtained by inducing a decrease in melting point and an increase in pyrolysis temperature while maintaining high hygroscopicity.

Example 3-1

In a flask, 30 g (0.352 mol) of monomer 2-pyrrolidone and 107.9 g (0.823 mol) of 6-aminocaproic acid were mixed in a nitrogen atmosphere, followed by 2 hours at 150 ° C, 2 hours at 230 ° C, and 6 hours at 250 ° C. Prepared by reaction.

The composition and production conditions of the polyamide copolymer prepared in Example 3-1 are summarized in the following [Table 5]. In addition, the brittleness or toughness of the polyamide copolymer prepared in Example 3-1 was measured, and the results are also shown in Table 5 below.

In addition, the polyamide copolymer prepared in Example 3-1 was dried in a vacuum oven for 4 hours at 80 ℃, dissolved in formic acid at 40 ℃ to measure the concentration and intrinsic viscosity, the results Also shown in Table 5 below.

Ingredients (mol) Brittleness
Evaluation results density
(g / ml) Intrinsic viscosity
(ml / g) 2-pyrrolidone 6-aminocaproic acid Example
3-1 30 70 toughness 0.3 0.4624 Nylon 6 100 toughness 0.756

Referring to [Table 5], the polyamide copolymer prepared in Example 3-1 showed a lower viscosity than nylon 6.

Example 4-1

In a flask, 301.7 g (2.926 mol) of monomeric γ-aminobutyric acid and 384 g (2.927 mol) of 6-aminocaproic acid were mixed in a nitrogen atmosphere, and at 160 ° C for 2 hours, 180 ° C for 1 hour, and 200 ° C for 30 ° C. After reacting for 2 hours at 240 ° C. for 1 minute, vacuum was maintained for 1 hour to remove unreacted material.

Example 4-2

In a flask, 350.7 g (3.394 mole) of monomeric γ-aminobutyric acid and 408.3 g (3.113 mole) of 6-aminocaproic acid were mixed under a nitrogen atmosphere, and the mixture was heated at 150 ° C for 2 hours, at 170 ° C for 2 hours, and at 190 ° C. After reacting for 30 minutes at 210 ° C. for 30 minutes and at 240 ° C. for 2 hours, vacuum was maintained for 1 hour to remove unreacted material.

The composition and production conditions of the polyamide copolymers prepared in Examples 4-1 to 4-2 are summarized in the following [Table 6].

Ingredients (mol) Reaction conditions Brittleness
Evaluation results γ-aminobutyric acid 6-aminocaproic acid Example 4-1 50 50 160 ℃ 2h, 180 ℃ 1h, 200 ℃ 30min, 220 ℃ 30min, 240 ℃ 2h brittle Example 4-2 50 50 150 ° C 2h, 170 ° C 2h, 190 ° C 30min, 210 ° C 30min, 240 ° C 2h brittle

Referring to [Table 6], it can be seen that a low molecular weight copolymer is synthesized under the polymerization conditions of Examples 4-1 to 4-2.

Example 5-1

In a flask, 50 g (0.485 mole) of monomer γ-aminobutyric acid and 82.3 g (0.727 mole) of caprolactam were mixed under a nitrogen atmosphere, and 2 hours at 150 ° C., 2 hours at 190 ° C., 2 hours at 220 ° C., 240 It was prepared by reacting for 2 hours at ℃.

Example 5-2

In a flask, 255 g (2.473 mole) of monomer γ-aminobutyric acid and 406.2 g (3.590 mole) of caprolactam were mixed in a flask, and at 160 ° C for 2 hours, at 180 ° C for 1 hour, and at 200 ° C for 1 hour, 220 It was prepared by reacting at 1 ° C. for 2 hours at 240 ° C.

The composition and production conditions of the polyamide copolymers prepared in Examples 5-1 to 5-2 are summarized in the following [Table 7].

Ingredients (mol) Reaction conditions Brittleness
Evaluation results γ-aminobutyric acid Caprolactam Example
5-1 40 60 150 ° C 2h, 190 ° C 2h, 220 ° C 2h, 240 ° C 2h brittle Example
5-2 40 60 160 ℃ 2h, 180 ℃ 1h, 200 ℃ 1h, 220 ℃ 1h, 240 ℃ 2h brittle

Referring to [Table 7], it can be seen that a low molecular weight copolymer is synthesized under the polymerization conditions of Examples 5-1 to 5-2.

Claims (5)

A method for producing a polyamide copolymer by polymerizing a) γ-aminobutyric acid and b) 12-aminododecanoic acid or 6-aminocaproic acid without using an initiator. The method of claim 1,
The reaction molar ratio of a) and b) is 1:99 to 99: 1 method for producing a polyamide copolymer. delete The method of claim 1,
The polymerization reaction is a method of producing a polyamide copolymer, characterized in that carried out in step by step temperature increase from 150 ℃ to 280 ℃. 5. The method of claim 4,
The temperature rising process is a method for producing a polyamide copolymer, characterized in that for 7 to 23 hours.

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